Rotary hammer



Dec. 19, 1939. J, BRQOKS 2,183,880

ROTARY HAMMER Filed April 11, 1938 INVENTOR J. P 5/?00/113 ATTORNEYJ 'atented Dec. 19, 1939 v ROTARY HAMMER James 1. Brooks, Concrete, Wash. Application April 11, 1938, SBliitlNO. 201,363

2 Claims.

This invention relates to improvements in what are known as rotary hammers and more particularly to hammers of that character used in rock crushers, cement manufacturing mills and the like, and which, in use, are subjected to considerable pounding and wear; the invention herein disclosed being an improvement in the hammer structure disclosed and claimed in United States Patent No. 1,940,116 issued to me on December 19, 1933, which patent features a hammer having a head portion that may be removed from its mounting shank for reversal thereon or for replacement by a new head.

In the hammer of the patent above mentioned, the head is provided across the top with a transverse recess which has its opposite side walls formed with inwardly projecting or what may be termed overhanging" shoulders, and between these side walls, the base of the recess is downwardly rounded. lT'he shank portion on which the hammer head is mounted has a rounded lower end surface adapted to seat against the rounded base of the head recess and has laterally projecting ears at its opposite edges adapted to be disposed beneath the overhanging shoulders of the recess to form an interlock between the head and the shank. Furthermore, in the patent, the shank portion of the hammer comprises two opposite side sections or plates, adapted to engage flatly together and against opposite faces of a web that extends across the recess, and to be held in place by a rivet extended through the two sections and through the web.

The hammer of the above mentioned patent,

' while having many advantages, also has a few undesirable features; for instance, the rounded base of the recess does not provide as solid or as substantial an abutment surface for the shank end as is desired, and also, by reason of its being downwardly rounded, the depth of the body is materially reduced and thus does not provide as -much extra depth to be taken up in wear as would be available if it were not so rounded; it being understood that use of the hammer causes an uneven wear and it must be periodically reversed in order to even it up. Another disadvantage is that the rivet which is, used to hold the sections of the shank together has been found to be very difilcult to remove when replacement or reversa1 of the hammer head was desired.

In view of the above remarks, relative to the hammer of the patent, it has been one of the objects of the present invention to provide certain improvements therein whereby to give the line 22 in Fig. 1.

hammer a longer life, as well as more rigidity while in use.

It-is also an object of the invention to provide a construction which makes possible the elimination of the objectionable rivet and thereby, to provide for easier and quicker assembling and disassembling of the head from the shank.

More specifically stated, the objects of the invention reside in the provision of a hammer having a head similar to that of the hammer of the patent except that the base.of the recess is perfectly flat between its opposite side walls,

and by reason of not being downwardly rounded, provides greater depth of body and affords a more solid abutment between the lower end of the shank and the hammer head.

Still further objects of the invention reside in the details of construction and in the combination of parts embodied in the device as will be hereinafter fully described.

In accomplishing these and other objects of the invention, I have provided the improved details of construction the preferred forms of which are illustrated 'in the accompanying drawing wherein- Fig. 1 is a side elevation of a rotary hammer constructed in accordance with the present invention.

Fig. 2 is a vertical cross section, as seen on the Fig. 3 is a view of the inner side of one of the retaining ears on the shank portion, particularly illustrating the beveled edge of the ear portion thereof.

Fig. 4 is an edge view of the same part.

Fig. 5 is a perspective view of the hammer showing the head portion disconnected from the 'shank portion to more clearly illustrate their construction.

To give a better understanding of the present invention, it will be here stated that such hammers are used in connection with ofi-center, or crank shaft mountings, and are so mounted thereon that when the shaft is rotated, the hammers swing outwardly to full length, and upon striking or impinging upon the rock or other objects, are free to swing rearwardly, thereby to allow their heads to pass the objects and the hammers then to swing out to full length for delivering another blow. In the present drawing, the hammer mounting is not shown.

Referring more in detail to the drawingl designates, in its entirety, the shank portion of the hammer, and '2 designates the head portion thereof. The shank portion is provided at With the hammer constructed in accordance with the foregoing, it is obvious that quick assemportion comprises two opposite side sections, or plates, la and lb, and that these are disposed flatly together.

nation of the pins and the machinery necessary to install same. It Another advantage is that by the provision of the flat bottomed recess, greater depth of hamto the disclosures herein made, but that it be given 16 scope of the invention.

Having thus described my invention, what I ment surfaces III which extend substantially the claim as new therein and desire to secure by Letters Patent is:

of the web and having fiat end surfaces in abut 30 in the flat base of the recess. Considering the parts of the hammer to be so constructed, its assembly will be as follows:

To assemble the shank plates la and lb with the ears being outwardly extended from the side edges 35 form to the bevel oithe coacting surfaces of the 40 edge of the overhanging h ulder l5 and al; prising a head block having a transverse flat bottherebeneath m a, substantially tlght mt; Th tomed recess across its top face with overhanging lower surfaces I 541 of the shoulders I5 are also Shoulders a s pp S a d ott m Sur beveled to insure ease of assembly and a, mor face of the recess having channels thereacross, perfect fittingin this connection, and a shank comprlsingtwo compleinental face By reason of design of these interlocking complementary, beveled ears, and the flat end sursurfaces of the shoulders being beveled to conform 60 surfaces of the shank against the fiat bottomed recess. 65

JAMES P. BROOKS. 

